General Pharmacy and Pharmacology Fundamentals

Pharmacology lecture notes covering pharmacokinetic parameters, routes of administration, transport mechanisms, drug metabolism, and pharmacodynamic principles.

Bioavailability (Bd)

The proportion of a drug dose that reaches the systemic circulation to produce its effect.

Half-life ($T_{1/2}$)

The time required for the plasma concentration of a drug to decrease by half.

Apparent Volume of Distribution ($V_d$)

A pharmacokinetic parameter representing the theoretical volume in which the total drug amount would need to be uniformly distributed to produce the observed blood plasma concentration.

Elimination coefficient ($K_e$)

The amount or percentage of a drug substance that is eliminated from the body within 24 hours.

Drug Clearance

The volume of plasma from which a drug is completely removed or purified per unit of time (usually expressed in minutes).

Sublingual Route

A route of administration where the drug is placed under the tongue; it features a thin, well-vascularized mucosa and bypasses the first hepatic passage as venous blood drains into the superior vena cava.

Rectal Route

An administration route characterized by a pH of 5.5 to 7.5 where the inferior and middle hemorrhoidal veins drain into the inferior vena cava, partially bypassing the liver.

Simple (Passive) Transport

A mechanism of drug absorption that occurs according to the concentration gradient without energy consumption; it includes simple diffusion and filtration.

Active Transport

A specialized transport mechanism that requires energy, uses transport systems, and can move substances against concentration or electrical gradients.

Facilitated Diffusion

A type of passive transport that does not require energy but is carried out with the help of specialized transport systems according to the concentration gradient.

Pinocytosis

A form of specialized transport involving the encapsulation of a drop of solute by the cell membrane to form a vesicle.

Free Fraction of Drugs

The pharmacologically active portion of a drug in the blood that is able to penetrate cell membranes and physiological barriers.

Coupled Fraction of Drugs

The portion of a drug bound to plasma proteins; it is pharmacologically inactive, acts as a blood deposit, and is metabolized and eliminated more slowly than the free fraction.

First-stage Biotransformation (Phase I)

Metabolic pathways including oxidation, reduction, and hydrolysis.

Second-stage Biotransformation (Phase II)

Conjugation pathways including sulfoconjugation, glucuroconjugation, acetylation, methylation, and glycine conjugation.

Microsomal Enzyme Inducers

Substances like Rifampicin, Phenobarbital, and Carbamazepine that increase the activity of liver enzymes, potentially decreasing the effectiveness of other drugs.

Microsomal Enzyme Suppressors

Substances like Cimetidine, Erythromycin, and Chloramphenicol that inhibit liver enzymes, potentially increasing drug toxicity.

Primary Action of Drugs

The initial interaction at the molecular, chemical, or biochemical level between drug molecules and the component molecules of living matter.

Pharmacodynamic Action

The result of the drug-body interaction manifesting through physiological and biochemical changes.

Global Pharmacological Effect

The complex of reactions triggered in the body as a result of the primary action, reflected at the systems level.

Therapeutic Index

The ratio of the average lethal dose ($DL_{50}$) to the average effective dose ($DE_{50}$).

Therapeutic Range

The ratio between the minimum therapeutic dose and the maximum therapeutic dose or the minimum toxic dose.

Rebound Phenomenon

An adverse reaction or a return of symptoms occurring upon the sudden suspension of drug administration.

Drug Tolerance

A phenomenon characterized by reduced receptor reactivity, increased metabolism, or homeostatic compensation leading to a decreased response to repeated drug doses.

Teratogenic Action

Unwanted effects of drugs during pregnancy that cause structural abnormalities in the developing fetus.